In the realm of fastening technology involving a substrate made of concrete, a distinction is made between insert elements that are cast into the concrete and anchors that are subsequently installed and that are anchored in the already hardened concrete. When it comes to the subsequently installed anchors, numerous types are known such as, for instance, expansion anchors (known, for example, from U.S. Pat. No. 5,176,481 A), screw anchors (known for example, from German patent application DE 10 2010 063675 A1), chemical anchor systems (known, for example, from U.S. Pat. No. 6,029,417 A) and undercut anchors (known, for example, from U.S. Pat. No. 6,238,128 B).
Alternative anchor concepts with a threaded sleeve and an expansion element are disclosed in German patent application DE 10 2006 025268 A1, in U.S. Pat. Appln. Publication No. 2012/0192404 A and in international patent application WO 0047905 A1.